This invention relates generally to percussion devices, and more particularly to piston valve which supply air to percussion devices.
Present piston valves for percussion devices include multiple parts. One embodiment of prior art percussion device includes the valve cover, disk valve, valve chest, belleville washers and housing plug. All of these parts, excluding the belleville washers, are formed from fully hardened steel which are expensive and complex to machine.
The prior piston valves require close tolerances between the piston valve sides and the valve bore since the two members are coupled together. These close tolerances require machining processes. Even after the finishing, the outside diameter of the piston valve often is somewhat eccentric with the valve bore. The piston valve with close tolerances often conflict with non-perpendicular shoulders of the housing.
The prior piston valves also utilize rigid valve pistons to control the flow of air to the piston. Since the rigid valve piston oscillates so many times within the valve bore, the selection of materials which to construct (and the associated heat, wear and shock) the piston valve cartridge from which can withstand these oscillations is extremely limited. Plastics, in particular, can not withstand the type of oscillations required for the prior rigid valve piston.
In the prior art configuration, the rigid valve pistons travel relative to the adjacent bore. Often the piston cavity will get dirty and clogged and restrict smooth passage of the valve piston within the valve cavity.
The foregoing illustrates limitations known to exist in present percussion apparatus piston valves. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.